Previous attempts to estimate labor supply functions based upon the constrained maximization of a utility function with leisure and income as arguments have assumed that all time not spent at work on the job is leisure time. In this paper we formulate a model of a household in which time is allocated between work on the job, leisure, and housework, where leisure is defined to be net of time spent on housework. The model is estimated under two alternative stochastic specifications and the results compared to those obtained (i) assuming that housework time is exogenous and (ii) assuming that housework time is part of leisure time.